Process for removal of sulfur, metals and asphalt from petroleum crudes



-dium, nickel, iron, sodium). 'fuel oils are valuable products for special applications PROCESS FGR REMOVAL 8F SULFUR, METALS AND ASPHALT FROM PETROLEUIVI @RUDES Carlo Padevani and Vittorio Berti, Milan, Italy No Drawing. Application March 22, 1956 Serial No. 573,106

Claims priority, application italy April z, 1955 4 Claims. or. 208-213) The present invention relates to a new method for refining petroleum crudes in order to improve the properties of crudes and of products therefrom derived. 'Ihis method meets 'in the same time the increased requirements of improved petroleum fractions and the need of refining low-grade petroleum crudes for removing asphaltic material, mineral matter (ash) and sulfur compounds.

' More particularly this method, as compared with conventional refining processes, oifers the following advantages:

(a) Accordingly, one object of the present invention is the production of residual fuel oils characterized by low asphalt content (very reduced values of Conradson carbon residues), by reduced viscosity, by lower sulfur content and by strongly reduced content of ashes vana- The so obtained residual as fuels in gas turbines, in domestic burners and in low and medium speed diesel-engines.

(b) Another object of the present invention is to make possible or easier and more efiicient the use of catalysts which are liable to be poisoned by the action of the above said components, in subsequent operations of reforming, cracking and refining hydrogenation.

Another object of the present invention is the great decrease of refinery equipment corrosion, and the reduced cost of the equipment maintenance and of expenses involved with treatment of the single products.

(d) A further object is the recovery of most of the sulfur contained in the crude as hydrogen sulfide, elemental sulfur, sulfuric acid.

(e) Another object is the recovery of mineral matter which is contained in the crude (particularly of the vanadium), as these materials are concentrated in a narrow fraction which can be easily handled.

(f) A further object is the reduction of air and liquid efiluents pollution in refining area, caused by sulfur compounds and by liquids which contain these compounds.

Several processes have been proposed and employed in view of eliminating sulfur, mineral matter or asphaltic material from petroleum crudes in which they are contained. l

'These processes are however generally limited to refining separated fractions or they require very expensive operating conditions as high pressure catalytic hydrogenation in several stages and/or use of costly and sensitive catalyts while other processes working under milder conditions and/or without any catalyst do not reach the different aims above mentioned or they reach only some of them and mostly partially.

It has now been found that it is possible to overcome atented Mar. 22, 1960 reaction zone containing as catalyst a mass having a high porosity and a high surface area (for instance specially activated coke, active coal, natural or synthetic aluminum hydrates, oxides or silicates) the space velocity being comprised between 0.5-5 volumes of liquid/hour/ per volume of contact mass. It has been found that by choosing the more appropriate rates of temperatures, pressure and space velocity, inside the above mentioned ranges, according to the nature of the feed, any sub stantial cracking or hydrogenation of hydrocarbons can be avoided, while the more heavy and unstable sulfur compounds are converted and the sulfur therein contained removed as hydrogen sulfide, and the asphaltic and resinous compounds, as well as the organometallic complexes (e.g. porphyrins) are decomposed and the asphaltic material coagulated as substances which can be easily filtered and decanted, including the mineral constituents, so allowing the subsequent separation by filtering, by centrifuging, by solvent extraction, by redistillation or by the other known methods.

It has been stated that the catalytic action of the masses having high porosity and high surface area is essential for the process and that the use of more costly and sensitive catalysts can be avoided.

The so refined crude oil, separated from asphaltic compounds, ashes and, eventually, also from high boiling fractions leaving as residue, fuel oils of high quality, may be treated, before the fractionation, or after the fractionation, by conventional processes of refining or by catalytic refining hydrogenation, so finely obtaining fractions of particular value of different volatility and boiling range. a

1 st example Crude oil from Middle East (Iraq), after having been preheated through a coil furnace, has been passed to a reaction zone, containing granulated activated carbon, with a space velocity of about 1-1.5 liquid volume/hour/ volume of the contact mass, at a temperature of 785- 825 F. and at a pressure of 425-500 p.s.i. in presence of hydrogen, and recirculatingthe hydrogen at a rate of about 8-16 standard cubic feet per pound of feedstock.

The mixed-phase products coming out of the contact zone have been condensed and separated in a liquid phase and in a gas-vapor phase. The liquid phase has been separated by filtration from the solid residues constituted by modified asphaltic products and by mineral substances and one portion of the filtered liquid has been fractionated, while another part, together with'the gases and light vapors separated in the above mentioned con"- densation, has been sent to a second reaction zone containing a catalyst having hydrogenating properties, which was able to improve and complete the transformation of residual sulfur compounds into hydrogen sulfide, and to operate a further refining of the hydrocarbons.

The volumetric yields of the first treatment were more than and those of second treatment (catalytic hydrogenation) were more than 98%.

The inspection of feedstock and of the products ob 2nd Crude 1st treat- Properties Oil treatment (Iraq) Inent (true catalytic) Total Products: i

Spec fic Gravity at 60 F.(15.5 C.). r 0. 849 0. 840 S. 816 Distillation ASTMI.B.P., C 27 29 32 Fraction boiling at:

212 F. (100 O,) percent in vol" 12. 5 12 302 F. (150 C.) do 29 30 3 43 45 49 54 53 do. 66 74 Residue above 572 F. (300 C.)

percent 41 34 20 Total-sulfur, percent vveight 2.1 1.33 0.14 Residue of distillation above 572 "00 C. Total sulfur, percent weight 3. 7 2. 9 Conradson Carbon, percent weight. 8.11 2. 78 Ashes, percent weight 0. 013 Or 0011 l Kinematic viscosity at 122 I (50 0.). 160. 2 29. 6 Englcr viscosity at 122 F. (50'C.) 22.2 97

l The residue above 572 F. of the product coming from the second treating (catalytic hydro-refining) has a Conradson carbon residue of 0.07 percent wt.

2nd example A crude oil from Iraq, like the one mentioned in the 1st example, has been treated under the same conditions but with the difierence that the. contact chamber-was filled up with granular activated metallurgical coke.

The analytical data on separated products have been 7 quite similar to those of the first example: particularly the pounds and containing organo metalliccomplexes and other ash-forming compounds, for producing highquality fuel oil having low viscosity and low content of asphalt, ashes and sulfur, comprising passing the oil at a temperature between 600 and 1060 F. and at a pressure between 70 to 710 p.s.i. into a contact chamber together with hydrogen in the presence of a mass of high porosity having a large surface area selected from the group consisting of granulated activated carbon and granulated activated metallurgical coke, maintaining the space velocity of the oil fed to the contact chamber between 0.5 and 5.0 volumes of liquid/hour/volume of contact mass, and maintaining a hydrogen recirculation at about 3.2 to 16 standard cu. ft./lb. of oil to promote decomposition of the organo metallic complexes and sulfur compounds and the coagulation of the asphalt-sues contained in the oil, and separating the decomposed organo metallic complexes and sulfur compounds and the coagulated asphaltenes from the oil.

2. A process forrefining crude and topped crude mineral oils having high contents of asphalt and sulfur compounds and containing organo metallic complexes and other ash-forming compounds, for producing high quality fuel oil having low viscosity and low content of asphalt, ashes and sulfur, comprising passing the oil at a tempera! ture between 785 and 825 F. and at a pressure between spasms 425 to 500 p.s.i. into a contact chamber together with hydrogen in the presence of a mass of high porosity having a large surface area selected from the group consisting of granulated activated carbon and granulated activated metallurgical coke, maintaining the space velocity of the oil fed to the contact chamber between 1.0 and 1.5 volumes of liquid/hour/volume of contact mass, and maintaining a hydrogen recirculation at about 8 to 16 standard cu. ft./lb. of oil to promote decomposition of the organo metallic complexes and sulfur compounds and the coagulation of the asphaltenes contained in the oil, and separating the decomposed organo metallic complexes and sulfur compounds and the coagulated asphaltenes fro'm the oil.

3. A process for refining crude and topped crude mineral oils having. high contents of asphalt and sulfur compounds and 'containing'organo metallic complexes and other ash-forming compounds, for producing high quality fuel oil having low viscosity and low content of asphalt, ashes and sulfur, comprising passing the oil at a temperature between 600 and 1060 F. and at a pressure between 70 to 710 psi. into a? contact chamber together with hydrogen in the presence of a mass of high porosity having a large surface area selected from the group consisting of granulated activated carbon and granulated activated metallurgical coke, maintainingthe space velocity of the oil fed to the contact chamber between 0.5 and 5.0 volumes of liquid/hour/volumeof contact mass, and maintaining a hydrogen recirculation at about 3.2 to 16 standard cu. ft./lb. of oil to promote decomposition of the organo metallic complexes and sulfur compounds and the coagulation of the asphaltenes contained in the oil, and recycling a portion of the refined oil through the contact chamber.

4. A process for refining crude and topped crude mineral oils having high contents of asphalt and sulfur compounds and containing organo metallic complexes and other ash-forming compounds, for producing high quality fuel oil having low viscosity and low content of asphalt, ashes and sulfur, comprising passing the oil at a tentperature between 600 and 1060 F. and at a pressure between 70 to 710 p.s.i. into a contact chamber together with hydrogen in the presence of a mass of high porosity having a large surface area selected from the group con sisting of granulated activated carbon and granulated activated metallurgical coke, maintaining the space velocity of the oil fed to the contact chamber between 0.5 and 5.0 volumes of liquid/hour/volume of contact mass, and

, maintaining a hydrogen recirculation at about 3.2 to 16 standard cu. ft./lb. of oil to promote decomposition of the organo metallic complexes and sulfur compounds and the coagulation of the asphaltenes contained in the oil,

and separating from the separated decomposed organo metallic complexes and sulfur compounds and the coagulated asphaltenes, the asphaltenes by dissolution.

References Cited in the file of this patent UNITED STATES PATENTS 

1. A PROCESS FOR REFINING CRUDE AND TOPPED CRUDE MINERAL OILS HAVING HIGH CONTENTS OF APLHALT AND SULFUR COMPOUNDS AND CONTAINING ORGANO METALLIC COMPLEXES AND OTHER ASH-FORMING COMPOUNDS, FOR PRODUCINC HIGH QUALITY FUEL OIL HAVING LOW VISCOSITY AND LOW CONTENT OF ASPHALT, ASHES AND SULFUR, COMPRISING PASSING THE OIL AT A TEMPERATURE BETWEEN 600* AND 1060*F. AND AT A PRESSURE BETWEEN 70 TO 710 P.S.I INTO A CONTACT CHAMBER TOGETHER WITH HYDROGEN IN THE PRESENCE OF A MASS OF HIGH POROSITY HAVING A LARGE SURFACE AREA SELECTED FROM THE GROUP CONSISTING OF GRANULATED ACTIVATED CARBON AND GRANULATED ACTIVATED METALLURGICAL COKE, MAINTAINING THE SPACE VELOCITY OF THE OIL FED TO THE CONTACT CHAMBER BETWEEN 0.5 AND 5.0 VOLUMES OF LIQUID/HOUR/VOLUME OF CONTACT MASS, AND MAINTAINING A HYDROGEN RECIRCULATION AT ABOUT 3.2 TO 16 STANDARD CU. FT/LB. OF OIL TO PROMOTE DECOMPOSITION OF THE ORGANO METALLIC COMPLEXES AND SULFUR COMPOUNDS AND THE COAGULATION OF THE ASPHALTENES CONTAINED IN THE OIL, AND SEPARATING THE DECOMPOSED ORGANO METALLIC COMPLEXES AND SULFUR COMPOUNDS AND THE COAGULATED ASPHALTENES FROM THE OIL. 